[U-Boot] [PATCH 01/31] powerpc: 8xx serial: add configurable SMC Rx buffer len

[U-Boot] [PATCH 01/31] powerpc: 8xx serial: add configurable SMC Rx buffer len

[Heiko Schocher]

This patch adds the configuration option CONFIG_SYS_SMC_RXBUFLEN.
With this option it is possible to allow the receive
buffer for the SMC on 8xx to be greater then 1. In case
CONFIG_SYS_SMC_RXBUFLEN == 1 or it is not defined this driver
works as the old version.

Signed-off-by: Heiko Schocher <hs@denx.de>
---
 cpu/mpc8xx/serial.c      |  102 +++++++++++++++++++++++++++++-----------------
 include/configs/mgsuvd.h |    1 +
 2 files changed, 65 insertions(+), 38 deletions(-)

diff --git a/cpu/mpc8xx/serial.c b/cpu/mpc8xx/serial.c
index bd90dcd..cb8c2e5 100644
--- a/cpu/mpc8xx/serial.c
+++ b/cpu/mpc8xx/serial.c
@@ -65,6 +65,18 @@ DECLARE_GLOBAL_DATA_PTR;

 #endif /* CONFIG_8xx_CONS_SCCx */

+typedef volatile struct serialbuffer {
+	cbd_t	rxbd;		/* Rx BD */
+	cbd_t	txbd;		/* Tx BD */
+#ifdef CONFIG_SYS_SMC_RXBUFLEN
+	uint	rxindex;	/* index for next character to read */
+	volatile uchar	rxbuf[CONFIG_SYS_SMC_RXBUFLEN];/* rx buffers */
+#else
+	volatile uchar	rxbuf[1];	/* rx buffers */
+#endif
+	volatile uchar	txbuf;	/* tx buffers */
+} serialbuffer_t;
+
 static void serial_setdivisor(volatile cpm8xx_t *cp)
 {
 	int divisor=(gd->cpu_clk + 8*gd->baudrate)/16/gd->baudrate;
@@ -113,12 +125,12 @@ static int smc_init (void)
 	volatile immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
 	volatile smc_t *sp;
 	volatile smc_uart_t *up;
-	volatile cbd_t *tbdf, *rbdf;
 	volatile cpm8xx_t *cp = &(im->im_cpm);
 #if (!defined(CONFIG_8xx_CONS_SMC1)) && (defined(CONFIG_MPC823) || defined(CONFIG_MPC850))
 	volatile iop8xx_t *ip = (iop8xx_t *)&(im->im_ioport);
 #endif
 	uint	dpaddr;
+	volatile serialbuffer_t *rtx;

 	/* initialize pointers to SMC */

@@ -194,23 +206,26 @@ static int smc_init (void)
 	 */

 #ifdef CONFIG_SYS_ALLOC_DPRAM
-	dpaddr = dpram_alloc_align (sizeof(cbd_t)*2 + 2, 8) ;
+	/* allocate
+	 * size of struct serialbuffer with bd rx/tx, buffer rx/tx and rx index
+	 */
+	dpaddr = dpram_alloc_align((sizeof(serialbuffer_t)), 8);
 #else
 	dpaddr = CPM_SERIAL_BASE ;
 #endif

+	rtx = (serialbuffer_t *)&cp->cp_dpmem[dpaddr];
 	/* Allocate space for two buffer descriptors in the DP ram.
 	 * For now, this address seems OK, but it may have to
 	 * change with newer versions of the firmware.
 	 * damm: allocating space after the two buffers for rx/tx data
 	 */

-	rbdf = (cbd_t *)&cp->cp_dpmem[dpaddr];
-	rbdf->cbd_bufaddr = (uint) (rbdf+2);
-	rbdf->cbd_sc = 0;
-	tbdf = rbdf + 1;
-	tbdf->cbd_bufaddr = ((uint) (rbdf+2)) + 1;
-	tbdf->cbd_sc = 0;
+	rtx->rxbd.cbd_bufaddr = (uint) &rtx->rxbuf;
+	rtx->rxbd.cbd_sc      = 0;
+
+	rtx->txbd.cbd_bufaddr = (uint) &rtx->txbuf;
+	rtx->txbd.cbd_sc      = 0;

 	/* Set up the uart parameters in the parameter ram.
 	*/
@@ -256,13 +271,21 @@ static int smc_init (void)

 	/* Make the first buffer the only buffer.
 	*/
-	tbdf->cbd_sc |= BD_SC_WRAP;
-	rbdf->cbd_sc |= BD_SC_EMPTY | BD_SC_WRAP;
+	rtx->txbd.cbd_sc |= BD_SC_WRAP;
+	rtx->rxbd.cbd_sc |= BD_SC_EMPTY | BD_SC_WRAP;

+#ifdef CONFIG_SYS_SMC_RXBUFLEN
+	/* multi-character receive.
+	*/
+	up->smc_mrblr = CONFIG_SYS_SMC_RXBUFLEN;
+	up->smc_maxidl = 10;
+	rtx->rxindex = 0;
+#else
 	/* Single character receive.
 	*/
 	up->smc_mrblr = 1;
 	up->smc_maxidl = 0;
+#endif

 	/* Initialize Tx/Rx parameters.
 	*/
@@ -285,11 +308,10 @@ static int smc_init (void)
 static void
 smc_putc(const char c)
 {
-	volatile cbd_t		*tbdf;
-	volatile char		*buf;
 	volatile smc_uart_t	*up;
 	volatile immap_t	*im = (immap_t *)CONFIG_SYS_IMMR;
 	volatile cpm8xx_t	*cpmp = &(im->im_cpm);
+	volatile serialbuffer_t	*rtx;

 #ifdef CONFIG_MODEM_SUPPORT
 	if (gd->be_quiet)
@@ -300,23 +322,18 @@ smc_putc(const char c)
 		smc_putc ('\r');

 	up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC];
-#ifdef CONFIG_SYS_SMC_UCODE_PATCH
-	up = (smc_uart_t *) &cpmp->cp_dpmem[up->smc_rpbase];
-#endif
+ #ifdef CONFIG_SYS_SMC_UCODE_PATCH
+	up = (smc_uart_t *)&cpmp->cp_dpmem[up->smc_rpbase];
+ #endif

-	tbdf = (cbd_t *)&cpmp->cp_dpmem[up->smc_tbase];
+	rtx = (serialbuffer_t *)&cpmp->cp_dpmem[up->smc_rbase];

-	/* Wait for last character to go.
-	*/
-
-	buf = (char *)tbdf->cbd_bufaddr;
-
-	*buf = c;
-	tbdf->cbd_datlen = 1;
-	tbdf->cbd_sc |= BD_SC_READY;
+	rtx->txbuf = c;
+	rtx->txbd.cbd_datlen = 1;
+	rtx->txbd.cbd_sc |= BD_SC_READY;
 	__asm__("eieio");

-	while (tbdf->cbd_sc & BD_SC_READY) {
+	while (rtx->txbd.cbd_sc & BD_SC_READY) {
 		WATCHDOG_RESET ();
 		__asm__("eieio");
 	}
@@ -333,49 +350,58 @@ smc_puts (const char *s)
 static int
 smc_getc(void)
 {
-	volatile cbd_t		*rbdf;
-	volatile unsigned char	*buf;
 	volatile smc_uart_t	*up;
 	volatile immap_t	*im = (immap_t *)CONFIG_SYS_IMMR;
 	volatile cpm8xx_t	*cpmp = &(im->im_cpm);
-	unsigned char		c;
+	volatile serialbuffer_t	*rtx;
+	unsigned char  c;

 	up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC];
 #ifdef CONFIG_SYS_SMC_UCODE_PATCH
 	up = (smc_uart_t *) &cpmp->cp_dpmem[up->smc_rpbase];
 #endif
-
-	rbdf = (cbd_t *)&cpmp->cp_dpmem[up->smc_rbase];
+	rtx = (serialbuffer_t *)&cpmp->cp_dpmem[up->smc_rbase];

 	/* Wait for character to show up.
 	*/
-	buf = (unsigned char *)rbdf->cbd_bufaddr;
-
-	while (rbdf->cbd_sc & BD_SC_EMPTY)
+	while (rtx->rxbd.cbd_sc & BD_SC_EMPTY)
 		WATCHDOG_RESET ();

-	c = *buf;
-	rbdf->cbd_sc |= BD_SC_EMPTY;
+#ifdef CONFIG_SYS_SMC_RXBUFLEN
+	/* the characters are read one by one,
+	 * use the rxindex to know the next char to deliver
+	 */
+	c = *(unsigned char *) (rtx->rxbd.cbd_bufaddr+rtx->rxindex);
+	rtx->rxindex++;

+	/* check if all char are readout, then make prepare for next receive */
+	if (rtx->rxindex >= rtx->rxbd.cbd_datlen) {
+		rtx->rxindex = 0;
+		rtx->rxbd.cbd_sc |= BD_SC_EMPTY;
+	}
+#else
+	c = *(unsigned char *) (rtx->rxbd.cbd_bufaddr);
+	rtx->rxbd.cbd_sc |= BD_SC_EMPTY;
+#endif
 	return(c);
 }

 static int
 smc_tstc(void)
 {
-	volatile cbd_t		*rbdf;
 	volatile smc_uart_t	*up;
 	volatile immap_t	*im = (immap_t *)CONFIG_SYS_IMMR;
 	volatile cpm8xx_t	*cpmp = &(im->im_cpm);
+	volatile serialbuffer_t	*rtx;

 	up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC];
 #ifdef CONFIG_SYS_SMC_UCODE_PATCH
 	up = (smc_uart_t *) &cpmp->cp_dpmem[up->smc_rpbase];
 #endif

-	rbdf = (cbd_t *)&cpmp->cp_dpmem[up->smc_rbase];
+	rtx = (serialbuffer_t *)&cpmp->cp_dpmem[up->smc_rbase];

-	return(!(rbdf->cbd_sc & BD_SC_EMPTY));
+	return !(rtx->rxbd.cbd_sc & BD_SC_EMPTY);
 }

 struct serial_device serial_smc_device =
diff --git a/include/configs/mgsuvd.h b/include/configs/mgsuvd.h
index f53b6d3..8f82751 100644
--- a/include/configs/mgsuvd.h
+++ b/include/configs/mgsuvd.h
@@ -44,6 +44,7 @@
 #define CONFIG_SYS_SMC_UCODE_PATCH	1	/* Relocate SMC1 */
 #define CONFIG_SYS_SMC_DPMEM_OFFSET	0x1fc0
 #define CONFIG_8xx_CONS_SMC1	1	/* Console is on SMC1		*/
+#define CONFIG_SYS_SMC_RXBUFLEN		16

 #define CONFIG_SYS_CPM_BOOTCOUNT_ADDR	0x1eb0	/* In case of SMC relocation, the
 					 * default value is not working */
-- 
1.6.0.6

-- 
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